Ejector fuseholder



June 30, 1964 W. C. LINTON EJECTOR FUSEHOLDER Filed Aug. 2, 1960 FIG. .1.

6 INVENTOR. W/LL /AM 0. L/NTO/V,

pointed out hereafter.

3,139,498 EJECTQER FUSEHOLDER William C. Linton, Washington, HQ, assignor to Fuse Indicator Corporation, Rocltvilie, Mal, a corporation of Maryland Filed Aug. 2, 196%, Ser. No. 46,949

V 8 Claims. (Cl. 200-421) The presentlinvention relates to holders for standard cartridge type fuses having the desirable indicators for annunciating the blown or ruptured condition of the fuse.

Suchfuseholders generally consist of a base attachable to a panel board, having an open end recess formed therein for receiving the fuse and a plug or cover for closing thefuse receiving recess. The cover for such 'fuseh'olders have heretofore'been connected to the base thereof by means of screw threads, bayonet locks and the like, which delay the replacement of the blown fuse causing the electrical current to remain open for an undesirable length of time and, therefore, an object of the present invention isto provide an automatic fuse ejector which, without delay, opens the cover of the fuseholder, ejects the fuse entirely from the holder. therefor,

retains the latter open for the manual insertion of a renewable fuse therein and by simple. closing of the cover the electrical circuit will again be completed.

indicating fuseholder that employs a lamp connected in series with the terminals of the holder, but in parallel with-the terminals of the fuse will permit the lamp to glow as long as current is supplied after the fuse has blown, but oftimes the current is interrupted by the blowing of the fuse and the function of the lamp as anindicator discontinues and it is another object of the invention to provide an indicator or annunciator that.

modified form of the invention on a reduced scale from that shown in FIG. 1.

PEG. 4 is a topjplan View of the same. FIG. is another sectional view of a still further modified form of the invention showing the cover of the.

fuseholder in open position due/to the blown condition of the fuse that has been entirely ejected therefrom.

FIG. 6 is a perspective view of the ambient compensatedgassemb-ly element of the fuseholder shown in FIG. 5.

FIG. 7 is a perspective view of the latch shown in the fuseholder of FIGJ 5, and 7 FIG. 8 is a perspective view of the latch element return spring. I

The fuseholder consists of a base or body 1 member molded from insulating material having an'open end recess 2 formed therein for receiving a standard cartridge type fuse 3. Pivotally connected tothe base 1 as at 4 is a cover 5 also molded from insulating material. A terminal 6 is connected by the rivet 7 to the lower end of the base 1 and the other or side terminal 8is connected to the base 1 by means of the drive screw 9 with one end 10 in the form of a contact blade that extendswithin the open end 2 of the base 1. Formed with the base 1 are screw threads 11 that receive the hex nut 12 for locking the base 1 to a panelboard 13. A gasket 14 is interposed between United States Patent 0 the hex nut 12 and the panelboard 13 and the outer face of the base 1 has a rubber gasket 15 seated therein in which projects the pointed rim 16 of the cover for sealing purposes.

Secured to the inner face. of the cover 5 by means of the drive screw 16A is an L-shaped conductor plate 17 and one end 18 of this plate 17 is retained in spring contact with the blade 10 of the terminal 8.

In FIG. 1 of the drawings a solenoid 19 is detachably connected by the screw threads 20 to the base 1. A lead wire 21. connects the terminal 6 to the coil of this solenoid 19. This solenoid 19 is of the communal type having the coil thereof connected by the insulated wire 22 to a lead extending through the usual soft iron armaturethereof to the set screw 23. Normally, the spring pressed armature is movably disposed in the axis of thesolenoid to elevate the set screw 23 in the position as shown, but when the solenoid is energized the armature is drawn inwardly and causes the set screw 23 to be lowered from the position as shown. A latch member 24 has side lugs 25 for pivotally supporting the same within the base 1 and a hook 26 capable of engaging the latch plate 17 for retaining the cover in closed position as shown. Below the fulcrum point of the latch member 24 is a section 27 extending at right angles thereto and having an elongated slot 28 formed therein through which passes the stem portion of the set screw 23. A coil spring 29A is positioned between the section 27 ofthe latch member and the head of the set screw 23. From the foregoing, it is apparent that when the electrical current may pass to the lead wire 21 from the terminal 6, it can pass to the solenoid 19, through the latch member 24 to the cover plate 17, and then to the side terminal 8. A coil spring 29 made from phosphorous bronze or other electrical conducting material,

is retained in the recess 2 of the base by means of the rivet 7 to form contact with the terminal 6, and when the fuse 3 is retained within the base, this coil spring 29 holds the upper end of the fuse 3 in contact with the head 30 of the cover drive screw 16A. Also retained in the recess 2 of the base by means of the rivet 7 is an ejector coil spring 31 preferably made from spring steel wire with an insulated sleeve 32 secured to its upper free end.

That form of invention as shown in FIG. 3, employs a latch member 33 made from a bimetallic strip consisting" of two lamina-ted strips of metal having. different linear coefiicient of expansion welded together. The side of higher coefficient of expansion is below the hooked end so that when the latch member is heated, the hooked end will be drawn from the contact plate 17' and thereby release the cover 5. A drive screw 34 connects the latch member. 33 with the extension wire 21 leading from the terminal 6 and retains the latch'upon the body 1 of the fuseholder.

s In that form of the invention shown in FIG. 5, I employ a bimetallic element-in coil form 35 having its outer free end connected to the extension wire 21 leading to the terminal 6 and its inner end connected to the shaft 36. This shaft is rotatably supported by the plug 37 secured within the extension 38 of the casing 1 of the fuseholder. Also connected to the shaft 36 but insulated therefrom is one end of ambient temperature bimetal control in coil form 39 and the outer free end of this coil extends within a slot 44 formed in the extension 38 of the fuseholder. The latch member 41 as best shown in FIG. 7 of the drawings, is pivotally supported by the lug extensions 42 within the body 1 of the fuseholder. Below this fulcrum point this latch member 41 has formed therewith a lug extension 43 contacting a leaf spring 44 which latter normaliy holds the hook 45 into engagement with the contact plate 17 of the cover 5. A key 46 is formed with the shaft 36 for holding the lug 4-3 in contact with the leaf spring 44.

When the cover of the fuseholder is closed, the current will pass from the terminal 6 through the fuse 3 to the terminal 8, but as a fuse blows the current will then pass from the terminal 6 tothe latch member and then to the terminal 8.

As the latch member is moved from the cover plate 17, the coil spring 31 will exert its pressure upon the fuse to open the cover and entirely eject the fuse 3 from the fuseholder, as is illustrated in FIG. 5 of the drawings. As soon as the cover is in open position, the contact 18 is separated from the contact thereby breaking the electrical circuit, but the open position of the cover 5 acts as an indication to announce the blown condition of the fuse and its ejection from the fuseholder.

As the fuse 3 is in series with the terminals 6 and 8 of the fuseholder, and the latchelement together with its electrical actuating device is also in series with the terminals 6 and 8, but in parallel with the fuse 3, it will be apparent that when the fuse blows or becomes ruptured the cover 5 will be opened and the fuse automatically ejectedfrom the fuseholder. By inserting a new fuse and closing the cover 5 the electrical current in which the fuse is included will again be completed.

I claim:

1. A fuseholder comprising a casing having an open end recess formed therein, contact terminals, a cover for closing the open end of said casing recess and retaining the fuse within said recess and in series with said contact terminals, a latch for retaining said cover in its closed position, a solenoid for actuating said latch whereby said cover retaining means will be released, means for connecting said solenoid in series with said terminals, but in parallel with the fuse, and means for ejecting the fuse from the recess of said casing when said cover has been released.

2. An ejector fuseholder comprising in combination a casing having an open end recess formed therein for receiving a cartridge type fuse, a pair ofcontact terminals carried by said casing, a cover pivotally connected to said casing for closing the open end ofthe recess formed in said casing, a latch plate secured to said cover and contacting one terminal of said fuse, a coil spring connecting the opposite terminal of said fuse with one of said contact terminals, the other of said contact terminals having contact with said latch plate whensaid cover is in closed position, a latch member pivotally supported in said casing and having a hook formed with one end thereof engageable with said latch plate, a shaft rotatably supportedwithin said casing and having a thermally responsive element in coil form connected thereto, an ambient thermal responsive coil connected to said shaft, but insulated therefrom, means for retaining said latch member in contact withsaid shaft, means for connecting saidthermally responsive element in coil form, said shaft, said latch member, and lock plate in series with said contact terminals,- but in parallel with the fuse whereby when the fuse blows the said latch member will be released from said latch plate for permitting said cover to be moved to open position, and a coil spring mounted in the recess of said casing for ejecting the fuse therefrom when said cover isperrnitted to move to its open position.

3. A fuseholder comprising a casing having an open end recess formed therein for receiving a fuse, contact terminals carried by said casing, means for retaining the fuse in contact with said terminals, electrically operated means for releasing said fuse retaining means, means for connecting said fuse releasing means in series with said contact terminals, but in parallel with said fuse whereby when the fuse becomes inoperative said fuse retaining means will be released and means for automatically ejecting the fuse from the open end recess of said casing when said fuse retaining means has been released.

4. A fuseholder comprising a casing having an open end recess formed therein for receiving a cartridge type fuse, a cover for closing the open end of the recess formed within said casing, contact terminals carried by said casing and extending within the recess of said casing, a contact plate carried by said cover, a switch for connecting said contact plate with one of said contact terminals, means for retaining said cover in a closed position closing said recess of said casing and retaining the fuse connected in series with said contact plate and the other of said contact terminals, means for releasing said cover retaining means upon the rupturing of said fuse, and means for automatically ejecting the fuse from the open end recess of said casing upon the release of said cover retaining means.

5. A fuseholder comprising in combination a casing having an open end recess formed therein for receiving a cartridge type fuse, contact terminals, means for connecting the fuse in series with said contact terminals, a mechanical" blown fuse indicator, electrical means "for operating said blown fuse indicator being connected in series with said contact terminals, but in parallel with the fuse when received within the recess of said casing and a switch included in said means for connecting the fuse in series with said contact terminals being connected to said indicator for being opened thereby when the fuse blows said indicator will visably indicate the blown condition of the fuse and said switch will be opened for disconnecting said fuse from said terminals.

6. A fuseholder comprising a casing having an 'open end recess therein for receiving a cartridge type fuse, a cover hingedly connected to said casing, means for retaining said cover in closed position bearing against an end of the fuse for holding the fuse in contact with saidterminals, a spring mounted within said casing for bearing against the other end of said fuse and means for releasing said cover retaining means upon the blowing of thefuse whereby said spring will eject the fuse entirely from said casing and cause said cover to move to its open position to thereby indicate the ejected position of the fuse.

7. A fuseholder comprising a casing having an open end recess for receiving a cartridge fuse therein, contact terminals, a cover for closing the open end of said casing recess and retaining the fuse within said recess andin series with said contact terminals, mechanical means for retaining said cover, in its closed position, electrically operated means for actuating said mechanical means to release said cover and means for connecting said electrically operated means in series with said terminals, but in parallel with the fuse for receiving current when the fuse becomes ruptured.

8. A fuseholder comprising a casing having an open end recess for receiving a cartridge fuse therein, contact terminals carried by said casing, a cover for closing the open end of said casing recess and retaining the fuse within said recess and in series with said contact terminal, a bimetallic latching means for retaining said cover in its closed position until said latching means is heated releasing said cover, and means for connecting said bimetallic latching means in series with said terminals, but in parallel with the fuse for receiving current and being heated when the fuse becomes ruptured.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A FUSEHOLDER COMPRISING A CASING HAVING AN OPEN END RECESS FORMED THEREIN, CONTACT TERMINALS, A COVER FOR CLOSING THE OPEN END OF SAID CASING RECESS AND RETAINING THE FUSE WITHIN SAID RECESS AND IN SERIES WITH SAID CONTACT TERMINALS, A LATCH FOR RETAINING SAID COVER IN ITS CLOSED POSITION, A SOLENOID FOR ACTUATING SAID LATCH WHEREBY SAID COVER RETAINING MEANS WILL BE RELEASED, MEANS FOR CONNECTING SAID SOLENOID IN SERIES WITH SAID TERMINALS, BUT IN PARALLEL WITH THE FUSE, AND MEANS FOR EJECTING THE FUSE FROM THE RECESS OF SAID CASING WHEN SAID COVER HAS BEEN RELEASED. 